富含裂隙水复杂地质深基坑锚索成孔技术研究

Study on Hole-forming Technology of Anchor Cable in Deep Foundation Pit With Complex Geology Rich in Fissure Water

文章主要介绍在广东省韩江高陂水利枢纽工程厂房尾水段深基坑边坡支护工程范围内地质构造复杂,风化界面起伏大,坡面裂隙水比较丰富,存在发育断层F8等地质条件下的深基坑锚索成孔工艺研究,提出对大倾角破碎裂片岩部位采用超前导管固结灌浆成孔工艺、对于穿越F8断裂带等地层部位采用钢套管跟进成孔工艺等多种成孔组合方式,成功解决了富含裂隙水复杂地质情况下采用常规干成孔工艺易造成孔内角砾岩崩落,钻杆抱死、断杆、塌孔等问题,经工程实践验证,此方法可行,解决了富含裂隙水复杂地质深基坑锚索成孔的施工问题,避免因塌孔造成工期延误和施工成本增加,同时也为今后类似地质条件下锚索成孔施工奠定了基础。

The Hanjiang Gaobri Water Control Project in Guangdong is mainly introduced in this paper.In the scope of the slope support engineering of deep foundation pit in the tail water section of the powerhouse,the geological structure is complex.The weathered interface undulates greatly and the slope surface fissure water is abundant.Based on the research of anchor cable hole forming technology in deep foundation pit under the geological conditions such as the development of faults F8,the advanced pipe consolidation grouting technology is proposed for the large dip angle fractured schist.For passing through the F8 fault zone and other stratum parts,a variety of hole forming combination methods such as steel casing follow-up hole forming technology were adopted,which successfully solved the problems such as breccia caving,drill pipe locking,broken rod and hole collapsing easily caused by conventional dry hole forming technology under complex geological conditions rich in fracture water.It is verified by engineering practice that this method is feasible,which solves the construction problem of anchor cable forming holes in complex deep foundation pit with rich fissure water,avoids the delay of construction period and increase of construction cost caused by hole collapse,and lays a foundation for anchor cable forming holes in similar geological conditions in the future.